The present invention relates to a collection container for bulk material with a conveying pump or a suction tube.
EP 0 750 966 A1 discloses a collection container that includes a conveying pump for conveying liquid media with production residues, for example, chips, coolants, and lubricants. The collection container is designed and constructed as a cylindrical pot with a substantially flat container bottom. A centrally supported removing arm operating above the container bottom guides the chips deposited on the container bottom to the conveying pump. However, such a collection container still leaves much to be desired.
Furthermore, DE 36 11 606 A1 discloses an apparatus for emptying a silo with a discharge opening arranged in the center, in which the bulk material is moved toward the center by means of a plurality of drag chains, which are mounted with their one end to a driven chain extending in the region of the container wall, and with its other end to a carrousel arranged in the center. The containers may be made circular or polygonal.
Disclosed in DE 94 19 379 U1 is a discharge device for hard-to-transport bulk materials, wherein in a cylindrical container, for example, a silo or the like, the bulk material is supplied to a discharge opening extending transversely across the bottom by means of a rigid removing arm, which connects to a rotating annular frame and pivot bearings in the center.
Further rotating devices for conveying bulk materials to a discharge opening or the like are known from DE 25 41 583 B2 and DE 82 34 176 U1.
DE 84 18 523 U1 discloses a discharge device in the form of a sliding frame for bunkers with a circular or a polygonal cross section. In this device, the sliding frame is reciprocated by means of two hydraulic cylinders, whereby the bulk material is supplied to a channel extending crosswise through the entire bunker.
In accordance with one aspect of the present invention, an improved collection container is provided. According to this aspect, the collection container includes a substantially level container bottom and a container wall extending upright with respect to the container bottom. Further in accordance with this aspect, at least one removing arm adapted for movement in the vicinity of the container bottom is provided, with the removing arm being arranged on a traction means, by which it can be moved. The removing arm is guided in the region of the container wall. As a result of gravity, the removing arm is held during its horizontal movement on the container bottom, and it mixes the bulk material that may be present in a dry form, or in a carrier medium, for example, water. When the bulk material is present in a dry form, the bulk material may be removed by suction through a tube, for example, via vacuum conveying air. When the bulk material is present in a liquid carrier medium, removal by suction will occur via a conveying pump. To ensure a satisfactory removing behavior, it is possible to reinforce the removing arm in a region further removed from the traction means. Based on its construction, it is possible to use the apparatus of the present invention in collection containers of nearly any desired shape with a substantially level bottom. In particular, the collection container may replace the collection tray in a metal-cutting machine.
In the collection container, the traction means circulates preferably in the vicinity of the container wall. It can thereby be ensured that abrasives are fully collected from the entire container bottom. In this connection, it is possible to provide a slide rail.
A satisfactory guidance of the removing arm is ensured by mounting it to the traction means via two points arranged in horizontally spaced relationship. According to a particularly preferred variant, the removing arm is mounted to the traction means in one point, and in a subsequent region, it is in contact with the container wall for sliding therealong. Preferably, the traction means is a chain, which runs over sprockets arranged in corners or curves of the container wall. A suitable number and arrangement of the sprockets permits realizing almost any desired shapes of collection containers. Furthermore, it is possible to realize in a simple manner modular systems for any dimensions of collection containers. As an alternative, embodiments using ropes and corresponding deflection pulleys are possible. Possible are sizes from 0.2 mxc3x970.2 m to 200 mxc3x9720 m. Likewise, a corresponding device may be used in a collection container of almost any desired design with substantially straight portions of the side walls.
A satisfactory clearing effect is provided by a removing arm having a V-shape in the direction of movement. In this instance, the extension of the legs is important and not the exact design of the intermediate area. Likewise, it is quite possible to use U-shaped removing arms with an open U, i.e., not parallel extending legs. Advantageously, the removing arm is made symmetrical with respect to its normal direction of movement, i.e. the angle bisecting line in the vertex is directed in the direction of movement. In this connection, the angle between the angle bisecting line and each leg of the removing arm should be at most 45xc2x0, preferably 30xc2x0, so as to effect an optimal conveyance of the bulk material being collected.
According to a further, particularly advantageous embodiment, the end of the removing arm close to the wall leads the end of the removing arms close to the interior. In this instance, the removing arm is preferably V-shaped, with its end close to the interior forming with respect to the direction of movement an angle of at least 90xc2x0, preferably 92xc2x0, and preferably at most 100xc2x0.
The suction effect of the conveying pump for the bulk material in the collection container may be assisted in that the conveying pump is arranged substantially directly above a region, which is passed by the removing arm. In this arrangement, the approximately V-shaped removing arm passes with its vertex in the vicinity of the center of the suction opening of the conveying pump. It is also possible to provide a plurality of conveying pumps and/or suction openings.
The use of a plurality of removing arms increases the conveying capacity. The lengthened or enlarged construction of a removing arm permits clearing even the center area of the collection container, and prevents the removing arms from overlapping. To this end, the leg directing toward the interior is made longer. Furthermore, a plurality of removing arms improve the proportioning of the bulk material supply for the conveying pump. Thus, smaller quantities of bulk material, which are easier to remove by suction, are supplied more often.
According to a preferred embodiment, the collection container includes a slide rail along the container wall, and on a leg that trails with respect to the direction of movement, the removing arm is provided with a projection, which lies against the slide rail.
Preferably, at least one inner removing arm with a drive is provided in the collection container inside the circulating traction means. It is also possible to provide a plurality of drives, each being associated to at least one removing arm. Such an arrangement is especially suitable for very large collection containers or for collection containers with such a plan form that it is not possible to clear the entire container bottom by the outer removing arm or arms.
According to a preferred embodiment, the inner removing arm rotates about a vertical axis, and advances the bulk material from the inside outward. Advantageous is a spiral configuration of the inner removing arm, with the spiral opening opposite to the direction of rotation. It will be also advantageous, when in the direction of movement or rotation, the inner removing arm is at least in part somewhat flattened, and includes on its side, in the direction of movement or rotation, a lateral surface serving as a slide section.
Preferably, the inner removing arm circulates faster than the outer removing arm, in particular the inner removing arm is driven in the same direction of movement or rotation for performing more circulations per unit time than the outer removing arm.
In order that the removing arms clear the area as completely as possible, the clearing areas of the outer and the inner removing arm or arms overlap. According to a preferred embodiment, the outer removing arm, in particular the longer outer removing arm is entrained by the faster circulating and thus passing inner removing arm so far that same is able to pass it, preferably without lifting it from the bottom. To this end, the outer removing arm is mounted to the traction means for pivoting in the direction of movement.
As an alternative, at least one drive is driven or controlled with the same direction of rotation as a function of the circulation speed of the traction means and/or of at least one additional drive, so that no interference occurs.
According to a further, preferred embodiment, the collection container accommodates one or more depressors, which press down and distribute accumulations of bulk material, so that the collection container can be kept very low, and the chip breaker is prevented from being hindered by accumulations. To this end, the depressor has preferably an inclination, which reduces the spacing between the depressor and the container bottom in the direction of movement of the removing arm.
According to another preferred embodiment, the collection container accommodates a centering device, which centers the bulk material caught by the removing arms such that it can be optimally taken hold of by the conveying pump. The centering device may be formed, for example, by brushes, push plates, cyclically revolving centering worms, or slides, or scavenging jets.
According to a particularly preferred embodiment, the bulk material is concentrated by the deflection of the removing arms resulting from their forward-back-forward movement.
To prevent an intake of the removing arm, same preferably includes a device which interrupts the generally flat surface, so as to enable a flow past the removing arm, to prevent the removing arm from being raised from the container bottom and the bulk material from possibly getting thereunder, and to avoid impedance to the forward movement of the removing arm. Preferably, the device is formed by ribs, which may project upward from the removing arm, but are preferably realized by providing cavities in the removing arm. As an alternative, it is also possible to provide in the removing arm openings, in particular bores.